Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/02—Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
  • A61B5/024—Measuring pulse rate or heart rate
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/02—Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
  • A61B5/024—Measuring pulse rate or heart rate
  • A61B5/02438—Measuring pulse rate or heart rate with portable devices, e.g. worn by the patient
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/02—Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
  • A61B5/024—Measuring pulse rate or heart rate
  • A61B5/0245—Measuring pulse rate or heart rate by using sensing means generating electric signals, i.e. ECG signals
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/02—Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
  • A61B5/026—Measuring blood flow
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/24—Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
  • A61B5/316—Modalities, i.e. specific diagnostic methods
  • A61B5/318—Heart-related electrical modalities, e.g. electrocardiography [ECG]
  • A61B5/346—Analysis of electrocardiograms
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/24—Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
  • A61B5/316—Modalities, i.e. specific diagnostic methods
  • A61B5/318—Heart-related electrical modalities, e.g. electrocardiography [ECG]
  • A61B5/346—Analysis of electrocardiograms
  • A61B5/349—Detecting specific parameters of the electrocardiograph cycle
  • A61B5/361—Detecting fibrillation
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/48—Other medical applications
  • A61B5/4836—Diagnosis combined with treatment in closed-loop systems or methods
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
  • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
  • A61B5/6813—Specially adapted to be attached to a specific body part
  • A61B5/6814—Head
  • A61B5/6815—Ear
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
  • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
  • A61B5/6813—Specially adapted to be attached to a specific body part
  • A61B5/6814—Head
  • A61B5/6815—Ear
  • A61B5/6817—Ear canal
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
  • A61B5/7203—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B7/00—Instruments for auscultation
  • A61B7/02—Stethoscopes
  • A61B7/04—Electric stethoscopes
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
  • A61N1/38—Applying electric currents by contact electrodes alternating or intermittent currents for producing shock effects
  • A61N1/39—Heart defibrillators
  • A61N1/3925—Monitoring; Protecting
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
  • A61N1/38—Applying electric currents by contact electrodes alternating or intermittent currents for producing shock effects
  • A61N1/39—Heart defibrillators
  • A61N1/3987—Heart defibrillators characterised by the timing or triggering of the shock

Definitions

• This invention relates generally to systems and methods for measuring heart activity and, more particularly, to sensing pulsatile blood flow using an electroacoustic transducer positioned proximate to the ear which detects pulse and provides audio output.
• PDAs Personal digital assistants
• portable digital music players are particularly popular as they can store a user's entire library of music and can be taken anywhere. They are particularly well suited for use while jogging such as they are not affected by movement.
• products have emerged that enable a portable digital music player to function as a pedometer, measuring a person's footsteps to provide an estimate of speed and distance traveled. Based on this information some products further provide an estimate of calories burned.
• a portable media playback device includes an electroacoustic transducer mounted to an ear piece adapted to be positioned within a user's ear.
• a receiving circuit and a controller are coupled to the transducer.
• the controller is programmed to selectively read media files form a media storage device and convert them to signals coupled to the transducer.
• the controller is further programmed to receive signals from the transducer and process the signals to determine the user's heart rate.
• a signal conditioning circuit receives the signals from the transducer and filters them to remove noise.
• the signal conditioning circuit may also perform common mode noise reduction using the signals from a pair of transducers.
• the controller receives signals from one transducer while outputting signals to another transducer.
• a heart monitoring system is incorporated into an automatic external defibrillator.
• the heart monitoring system receives signals from an electroacoustic transducer, such as an earphone mounted within an ear piece, and processes the signals to determine the presence of pulsatile blood flow in a subject.
• This arrangement is useful for confirming an ECG analysis that indicates a shock is needed by the absence of sensed pulsatile activity from the patient's ear canal.
• a sensed pulsatile activity in the patient's ear contra- indicates the need for a resuscitation shock.
• the arrangement is especially useful in a "pulseless electrical activity" (PEA) situation, where the lack of a sensed pulse in the ear canal will contradict an ECG analysis that indicates the presence of effective electrical activity in the heart.
• PDA pulseless electrical activity
• Figure 1 is a schematic block diagram of a system for measuring a person's heart rate in accordance with an embodiment of the present invention.
• Figure 2 is a graph plotting the output of an electroacoustic transducer conditioned to facilitate extraction of a person's heart rate.
• Figure 3 is a flow diagram for measuring a person's heart rate in accordance with an embodiment of the present invention.
• Figure 4 is a schematic block diagram of a media playback device including a system for measuring a person's heart rate in accordance with an embodiment of the present invention.
• Figure 5 is a flow diagram of a method for incorporating heart rate monitoring into media playback in accordance with an embodiment of the present invention.
• Figure 6 is a flow diagram of an alternative method for incorporating heart rate monitoring into media playback in accordance with an embodiment of the present invention.
• Figure 7 is a schematic block diagram of an automatic external defibrillator
• AED incorporating a system for indicating the presence of pulsatile blood flow in accordance with an embodiment of the present invention.
• a heart monitoring system 10 includes an electroacoustic transducer 12, such as an audio earphone, coupled to a receiver 14.
• the transducer 12 is mounted within an ear piece 16 that is adapted to mount to a user's ear.
• the ear piece 16 may be positioned around the user's auricle, nested in the user's auricle, or inserted in the user's ear canal.
• the receiver 14 receives signals from the transducer 12 and outputs them to a signal conditioning module 18.
• the signal conditioning module 18 amplifies and removes noise from the signal.
• the signal conditioning module 18 performs low pass filtering on the signal to remove frequency content that is the result of noise.
• two transducers 12 are used, one for each of the user's ears. In such embodiments, the signal conditioning module 18 may use signals from both transducers to perform common mode noise rejection.
• the output of the signal conditioning module 18 is provided to a controller 20 including an extraction module 22, a monitoring module 24, and an output module 26.
• the signal conditioning module 18 is also incorporated into the controller 20.
• the extraction module 22 analyzes the conditioned signal in order to isolate individual heart beats. As shown in the plots 28a, 28b, which represent signals detected in a user's two ears, portions of the received pulsatile signals correspond to a person's heart beat including portions 30a, 30b corresponding to the Si and S 2 tones, respectively, of the heart beat. Also apparent is a low pressure portion 30c occurring between the Si and S 2 tones. As is apparent in Figure 2, the heart beat may be readily identified in one ear or the other. Accordingly, the extraction module 22 may use one, both, or a weighted combination, of the received signals in order to determine the user's pulsatile blood flow and, if desired, measurements thereof such as heart rate.
• the extraction module 22 may, for example, evaluate the quality of the signal from each ear and use only the one having the highest quality to isolate the heart rate. Quality may be determined by evaluating and comparing the signal-to-noise ratio of the signals as known in the art. In other embodiments the signals from the two ears may be correlated to identify the heart beat signal.
• the extraction module 22 may extract the heart beats from the signal from the transducer 12, or signals from two transducers 12, by locating the Si and S 2 tones. As is apparent in plot 28b, the low pressure portion 30c between the Si and S 2 tones 30a, 30b is of relatively large magnitude even though the Si and S 2 tones are of relatively weak magnitude. Accordingly, the extraction module 22 may identify heart beats by identifying the low pressure portion 30c in place of or in addition to locating the Si and S 2 tones 30a, 30b. In some embodiments, the extraction module 22 identifies individual heart beats by using conventional methods, such as those disclosed in U.S. Patents 4,549,551 and 7,135,002.
• the monitoring module 24 evaluates the timing of the beats to determine the user's heart rate.
• the monitoring module 24 may record the heart rate over time and produce values derived from the recorded data, such as average heart rate, minimum and maximum heart rate, amount of time the heart rate falls within a target range of heart rates. For example, a user may input into the monitoring module a range of heart rates within which the user's heart rate should remain during a workout to improve results and avoid injury. In some embodiment, a user may input a maximum heart rate and the monitoring module will calculate a range of heart rates in which the user's heart rate should remain to improve results. In some embodiments, the monitoring module 24 produces a plot showing variation in heart rate over time.
• the output module 26 outputs the heart rate and values derived from the heart rate to the user.
• the output module 26 may output the data to a display device (not shown) coupled to the controller 20, such as an LCD or other digital display.
• the output module 26 may generate a audio message that is output through the earphone.
• the output module 26 produces a wireless signal that is received by another device having a receiver and a display, and used to generate an output for display to a user.
• a method 32 for measuring a heart rate includes inserting an electroacoustic transducer into a person's ear at step 34.
• Step 34 may include positioning the transducer around the person's ear or into the person's auricle or ear canal.
• sound waves induced in the person's tympanum by blood flow therethrough are communicated to the transducer and converted into electrical signals by the transducer.
• the electrical signals are conditioned to remove noise.
• Step 38 may include one or both of low pass filtering and common mode noise rejection using the output of two transducers placed in two ears.
• the conditioned signal is processed to extract a person's heart beats and at step 42 the beats are monitored to calculate a heart rate.
• Other values related to the heart rate over time can be calculated as well, such as average, maximum, and minimum heart rate during a monitoring period or the duration of time in which the heart rate has been within a target range.
• an output is produced indicating the user's heart rate and/or the values corresponding to the heart rate over time. Producing an output 44 may include producing a visual display or an audible verbal message presented over the same transducer used to detect the person's heart rate.
• a heart rate monitoring system is incorporated into a portable media playback device 46.
• the electroacoustic transducers 12 may be embodied as earphone 48, such as the illustrated earphone adapted to be inserted within the auricle of a user, or as any other type of earphone known in the art.
• the device 46 includes a media reader 50 for reading media data from a media storage device 52, such as a flash memory, hard drive, compact disc, audio tape, or the like.
• the media data from the media reader 50 is provided to an audio driver 54 that converts the media data into electrical signals that are coupled to the earphone 48 to produce sound.
• the media reader 50 and audio driver 54 are controlled by a controller 56 incorporating an extraction module 22, monitoring module 24, and output module 26 of the heart rate monitoring system.
• the earphone 48 may also be coupled to the controller 56 by a receiver 14 and signal conditioning module 18.
• the controller 56 may be coupled to a display 58, such as an LCD or other display device, for presenting information to a user.
• the controller 56 may include a media selection module 62 that receives one or more inputs from one or more input devices 60 such as a touch pad and/or one or more buttons.
• the media selection module 62 receives the inputs and selects a media file from the media storage device 52 for playback based on the inputs.
• the controller 56 may further include a mode selection module 64.
• the mode selection module 64 selects whether the media playback device 46 is to function as a media playback device or as a heart monitor. In some embodiments, the mode selection module 64 selects which of the earphones 48 is to output audio signals and which is to receive signals for monitoring a user's heart rate. For example, the mode selection module 64 may cause one earphone to output music while the other earphone is simultaneously measuring the user's heart rate.
• the mode selection module 64 measures the user's heart rate between playback of media files. For example, the mode selection module 64 may switch the mode from playback to heart rate monitoring for a brief period, such as two to five seconds after a song, during which period the user's heart rate is monitored by receiving signals at the receiver and processing them as discussed above. The mode selection module 64 may then cause the media reader 50 and audio driver 54 to output another song to the earphone 48.
• a method 65 for combining media playback with heart rate monitoring may include inserting an earpiece in a user's ear, either in the auricle or ear canal, at step 66.
• the method 64 further includes reading a first media file from a media storage device at step 68 and outputting the media file to an earpiece at step 70.
• signals from the earpiece are received following output of the media file at step 70.
• the received signals are processed to extract the user's heart rate.
• the heart rate is output, such as by means of a display or verbal message output over the earpiece.
• a second media file is read from the media storage device and at step 80 the second media file is output to the earpiece.
• Method 82 includes inserting two earphones in a user's ears, either in the auricles or ear canals, at step 84.
• the method 82 further includes reading a media file from a media storage device at step 86 and outputting the media file to the earphones at step 88.
• Output to one of the earphones is interrupted at step 90 while continuing playback on the other earphone.
• Signals are received from the interrupted earphone at step 92.
• the received signals are processed to extract the user's heart rate.
• the heart rate is output, such as by means of a display or verbal message output over the earphone. In some embodiments, the output is delayed until requested by a user, such as in response to an input. In such embodiments, step 96 may be replaced with storing the heart rate for later presentation.
• the media file is again output to both earphones.
• the method 82 is repeated with playback to the other earphone being interrupted, at step 90.
• the method 82 may further include comparing the signals received from each ear during step 92 to determine which ear provides a better signals to noise ratio. Following this comparison, in subsequent iterations of the method 82, only the ear found to have the higher signal to noise ratio is interrupted at step 90.
• a blood flow monitoring system 10 is incorporated into an automatic external defibrillator (AED) 100.
• the AED includes electrodes 102 for contacting a victim's skin when administering a shock.
• the AED 100 further includes a power source 104 providing electrical power for delivering a shock.
• the AED 100 further includes a controller 106 that is programmed to control the delivery of electrical power from the power source 102 to the electrodes 100.
• the controller 106 also detects the electrical activity of the victim's heart through the electrodes 102 and analyzes the electrical activity to determine whether a shock should be administered.
• the controller 106 further includes the extraction module 22, monitoring module 24, and output module 26 as discussed above for monitoring a patient's pulsatile blood flow using electroacoustic transducers 12, such as headphones or earphones.
• the AED 100 likewise includes a receiver 14 and signal conditioner 18 for receiving signals from the transducers 12.
• the AED 100 includes a display 108 and the controller is programmed to display instructions for operating the AED on the display 106.
• the output module 26 of the heart monitoring system may determine that the patient is presenting pulsatile blood flow from the detection of acoustic signals in the ear canal as discussed above and output to the display 108 an indication of the blood flow condition and other values determined by monitoring the pulsatile signals, when present, over time.
• the blood flow indication signal is output as an audible signal.

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• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Animal Behavior & Ethology (AREA)
• Physics & Mathematics (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Cardiology (AREA)
• Medical Informatics (AREA)
• Molecular Biology (AREA)
• Surgery (AREA)
• Biophysics (AREA)
• Pathology (AREA)
• Physiology (AREA)
• Otolaryngology (AREA)
• Acoustics & Sound (AREA)
• Signal Processing (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Radiology & Medical Imaging (AREA)
• Artificial Intelligence (AREA)
• Hematology (AREA)
• Computer Vision & Pattern Recognition (AREA)
• Psychiatry (AREA)
• Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
• Electrotherapy Devices (AREA)
• Headphones And Earphones (AREA)
• Circuit For Audible Band Transducer (AREA)
• Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)
• Measuring And Recording Apparatus For Diagnosis (AREA)

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• 2008
  • 2008-11-18 PL PL08854274T patent/PL2214554T3/pl unknown
  • 2008-11-18 EP EP10172784A patent/EP2314212A1/de not_active Withdrawn
  • 2008-11-18 CN CN2008801178080A patent/CN101873826B/zh active Active
  • 2008-11-18 ES ES08854274T patent/ES2380881T3/es active Active
  • 2008-11-18 WO PCT/IB2008/054840 patent/WO2009069037A2/en not_active Ceased
  • 2008-11-18 JP JP2010534581A patent/JP5513401B2/ja active Active
  • 2008-11-18 US US12/744,954 patent/US9386929B2/en active Active
  • 2008-11-18 AT AT08854274T patent/ATE541507T1/de active
  • 2008-11-18 EP EP08854274A patent/EP2214554B1/de active Active
• 2013
  • 2013-11-14 JP JP2013235559A patent/JP6118234B2/ja active Active
• 2015
  • 2015-12-18 US US14/974,789 patent/US9877661B2/en active Active

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